1. Technical Field
The present invention relates to an A/D conversion circuit, an electronic apparatus, and an A/D conversion method.
2. Related Art
From the past, as an A/D conversion circuit for converting analog signals into digital data, there has been known a successive-approximation type A/D conversion circuit. The successive-approximation type A/D conversion circuit is provided with a comparison circuit, a successive-approximation register, and a D/A conversion circuit, and performs A/D conversion on the signal, which is obtained by sampling (performing a sample and hold operation on) an input signal, by the successive approximation action, thereby outputting the digital data. As a related art technology of such a successive approximation type A/D conversion circuit, there is known a technology disclosed in JP-A-8-321779.
In such an A/D conversion circuit, the most part of the conversion accuracy depends on the accuracy of the D/A conversion circuit. Further, when attempting to improve the accuracy of the D/A conversion circuit, the size of the circuit is enlarged due to the area of capacitors (in the case of a charge redistribution type) or the area of resistors (in the case of a ladder resistor type). On the other hand, if devices are added to the D/A conversion circuit in order for preventing the increase in the circuit size, then, there arises the problem that so-called missing code is caused due to an error of differential non-linearity or integral non-linearity.